and again, turning in 4wd, where the wheels don't turn at different speeds as an AWD system would allow, which causes the inner wheel to break traction,,,, that grip to the road that you would have had if you left it in 2wd. Once you break static friction your traction decreases. I doubt anywhere in the manual it states to use 4wd for turning on wet roads. You're way more likely to understeer on a wet road using 4wd than you are 2wd.
It's the same reason you shouldn't drive on dry pavement in 4wd, because when you turn, it induces bind. Why can you use 4wd offroad? Because the loose ground allows the inner tire to SLIP. On wet roads where it is slippery, you won't get the bind, you'll allow the tire to SLIP and not bind. The instant you have SLIP, you have less traction.
On loose offroad conditions or in deep snow or on ice where you're slipping anyway, when all you've got is kinetic friction anyway, yes 4wd helps you track. On wet roads where you would have static friction, 4wd does nothing for you turning.
And also roads are the most dangerous after a rain just starts until the oils and debris are washed off the roads. It can be a light mist and they can be very slick. After it's rained for a while, it can be terrential downpours, and the road won't be any more slippery than a light rain.
But again, if you feel you need 4wd to be able to drive on wet roads, by all means, do what you think you need to do to handle an automobile. For everyone else with simple driving skills, there's absolutely no need to run 4wd in the rain, other than it helps you compensate for something else that even the almighty raptor itself must not be sufficient at when it's in 2wd mode LOL
It's the same reason you shouldn't drive on dry pavement in 4wd, because when you turn, it induces bind. Why can you use 4wd offroad? Because the loose ground allows the inner tire to SLIP. On wet roads where it is slippery, you won't get the bind, you'll allow the tire to SLIP and not bind. The instant you have SLIP, you have less traction.
On loose offroad conditions or in deep snow or on ice where you're slipping anyway, when all you've got is kinetic friction anyway, yes 4wd helps you track. On wet roads where you would have static friction, 4wd does nothing for you turning.
And also roads are the most dangerous after a rain just starts until the oils and debris are washed off the roads. It can be a light mist and they can be very slick. After it's rained for a while, it can be terrential downpours, and the road won't be any more slippery than a light rain.
But again, if you feel you need 4wd to be able to drive on wet roads, by all means, do what you think you need to do to handle an automobile. For everyone else with simple driving skills, there's absolutely no need to run 4wd in the rain, other than it helps you compensate for something else that even the almighty raptor itself must not be sufficient at when it's in 2wd mode LOL
Yup there won't be as much wear on your vehicle because the inside tire won't bind, it will slip on a slippery road, but your handling goes to chit compared to 2wd on wet roads where no front tires are slipping, and there's no understeer like there is trying to turn in 4wd. 
